Microprocessor-Based Electrical Re-Phasing for Power Factor Correction
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Solution Overview
Problem
Existing methods for automatically re-phasing current in domestic electrical networks are unreliable and often result in a high margin of error, with the insertion of excessive capacitive loads and difficulty in distinguishing inductive load components, leading to inefficient energy use and economic penalties.
Innovation Solution
A method and apparatus utilizing a microprocessor-based system with sensors and microcapacitors to detect and adjust electrical parameters, automatically inserting or removing capacitive loads to optimize the power factor, featuring a central processing unit, current and voltage sensors, and opto-electronic switches for precise control and minimal error.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If traditional automatic re-phasing methods are used, then capacitive loads are inserted to correct phase shift, but the method results in high margin of error and excessive capacitive load insertion
Solution Approach 1:
The patent replaces traditional mechanical or analog re-phasing control systems with a microprocessor-based digital control system. The microprocessor accurately measures the phase shift between voltage and current, calculates the precise capacitive compensation needed, and controls switching devices to insert or remove microcapacitors accordingly. This digital substitution eliminates the high margin of error inherent in traditional methods and achieves power factor correction with precision exceeding 0.99.
Solution Approach 2:
The patent implements a feedback control mechanism where the microprocessor continuously monitors the phase shift between voltage and current signals, compares the actual power factor with the target value, and dynamically adjusts the capacitive compensation by switching microcapacitors in or out of the circuit. This closed-loop feedback system ensures accurate and reliable power factor correction while preventing excessive capacitive load insertion.
2Reliability
If banks of correction capacitors are connected in parallel with inductive loads, then power factor is improved, but the system cannot accurately distinguish inductive load components from resistive loads
Solution Approach 1:
The patent employs a microprocessor-based system that uses digital signal processing to analyze the electrical characteristics of connected loads. By measuring the phase relationship between voltage and current and calculating impedance characteristics, the microprocessor can accurately distinguish inductive loads from resistive loads without requiring complex hardware circuitry for load analysis. This digital approach simplifies the overall device complexity while improving identification accuracy.
Solution Approach 2:
The patent changes the approach from hardware-based load discrimination to parameter-based analysis by the microprocessor. The system measures electrical parameters such as phase angle, impedance, and power factor, and uses these parameters to identify and classify loads. This parameter-driven method enables accurate distinction between inductive and resistive loads through software algorithms rather than complex hardware circuits.
3Loss of energy
If excessive capacitive loads are inserted to correct phase shift, then power factor increases, but energy wastage increases due to over-correction
Solution Approach 1:
The patent implements precise feedback control where the microprocessor continuously monitors the power factor and dynamically adjusts capacitive compensation. The system calculates the exact amount of capacitive reactance needed to achieve the target power factor (typically 0.99) and controls switching devices to insert or remove specific numbers of microcapacitors. This precise feedback mechanism prevents over-correction and the associated energy wastage while maintaining high automation control precision.
Solution Approach 2:
The patent applies the principle of partial action by using multiple microcapacitors of different values that can be switched in or out in specific combinations. Rather than using a single large capacitor that may cause over-correction, the system selectively activates subsets of capacitors to achieve the precise compensation needed, thereby avoiding excessive capacitive loading and energy wastage.
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
The solution achieves a power factor close to 0.99, reducing energy wastage and penalties by accurately determining and correcting phase shifts, ensuring efficient energy use with reduced environmental impact and ease of installation.
Implementation Method 1
a plurality of microcapacities (80) operatively arranged between a plurality of switches (100) and the electrical network RE
Implementation Method 2
control means (90) of the plurality of microcapacities (80) and a plurality of switches (100), in particular opto-electronic switches
Data Source
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AI summary
Method (200) for automatically re-phasing the current of a domestic electrical network or similar, through an automatic electrical re-phasing apparatus operatively connected to such an electrical network, comprising steps of: - comparing (202) for a first portion of a set execution time period, through a central processing unit (10) of such an electrical re-phasing apparatus, electrical operating parameters detected by the electrical network with respective preset electrical reference operating parameters, said step of comparing (202) comprising a step of calculating (205) through the central processing unit, based on such electrical operating parameters, a phase shift representative of the power factor; - sampling (209), through the central processing unit, in the first portion of the set execution time period, such electrical operating parameters detected by the electrical network and the calculated phase shift; calculating (210), through the processing unit, in the first portion of the set execution time period, a correction value of the calculated phase shift; controlling (211), through the central processing unit, in a second portion of the set execution time period, distinct from the first portion, the insertion or removal of a quantity of a plurality of microcapacities from the electrical network based on such a calculated correction value.